SysML FAQ: What is the best free and open-source SysML tool?

Since there are many Free & Open Source Software (FOSS) UML tools available, a common Google query is "What is the best [free | open source] SysML tool?" Indeed, there are a few FOSS SysML tools that support drawing SysML 1.x notation, but relatively few that support the SysML advanced features that are essential for scalable and robust Model-Based Systems Engineering (MBSE) techniques.

You can find the few FOSS SysML tools that support drawing SysML 1.x notation, as well as relatively high-quality/low-cost commercial SysML tools that support SysML's advanced features (e.g., Behavioral and Parametric diagram simulation, import/export Requirements), on the SysML Tools web, which rates both commercial and FOSS SysML tools.